Installing GPS tracker

Hello everyone,
I'm new here, but I'm quite desperate so I'm resorting to forums.
I have a GPS tracker that I would like to install onto my Prius, but my main issue is that there are no guides or videos on the wiring in the car, and being a hybrid and rather non-conventional, it is extremely difficult for me to figure out the wiring on it.
Main goals: Locate stable +12v, locate ignition wire, locate any wire that if cut, will safely prevent the car from starting (I will place a relay on this wire that I will be able to open on command remotely, and it is important for it to be able to stop, but not start, so the start/stop button does not cut it). I had taken apart the dashboard, and found nothing other than a ridiculous amount of different wires that make no sense at all to me.
Any insight or just tip on where to look for even just wiring diagrams would be incredibly useful, and I thank anyone in advance for even just taking the time to read this.